cheers Frank...I never really understood (or experimented) much about the "pancake effect"...I will re-jig the (bigger) stones some for the next scene...I am getting some progress with a method of colouring the stones, but it is not perfect (yet!)... again, just too subtle!!!
I may have to go back to the drawing board!
one shader set for the general rock surface(s) with a simple modifier for single or groups of stones??
don't really know yet...
I will keep you posted!

edit:
btw glad you liked the cirrus!!!
if I get around to it I may post a clipfile...after the weekend...